SAR SH 522 Lecture Notes - Lecture 11: Alveolar Pressure, Vocal Folds, Exhalation

• School: Boston University
• Department: Speech, Language & Hearing Sciences
• Course: SAR SH 522
• Professor: Polyak

Document Summary

We can look at lung pressure throughout tidal respiration without speech. When we are tidal breathing, we contact our diaphragm, creating more space in the thorax. Alveolar pressure drops to -2, forcing air into our system. Air comes in to stabilize and equalize pressure. This is what we see when we start inhaling. Lung pressure will go back to 0, like atmospheric pressure. After we are done with the inhale, right before exhale, we relax our muscles and intra pleural pressure is at its most negative (10cm h2o). Air will then go out and we exhale and everything goes back to 0, except for pleural pressure which is -6 at rest. If the lung pressure is negative when we inhale, so all other pressures will be negative too. If the lung pressure is positive when we exhale, all other pressures will be positive too. Speech always happens on the exhalation and vocal folds are closed when we are talking.